CVE-2021-26857
HIGH KEV RANSOMWAREMicrosoft Exchange Server - Insecure Deserialization
Title source: ruleDescription
Microsoft Exchange Server Remote Code Execution Vulnerability
Exploits (1)
nomisec
WORKING POC
112 stars
by sirpedrotavares · remote
https://github.com/sirpedrotavares/Proxylogon-exploit
References (2)
Core 2
Core References
Patch, Vendor Advisory x_refsource_misc
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26857
US Government Resource
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26857
Scores
CVSS v3
7.8
EPSS
0.4099
EPSS Percentile
97.4%
Attack Vector
LOCAL
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CISA SSVC
Vulnrichment
Exploitation
active
Automatable
no
Technical Impact
total
Details
CISA KEV
2021-11-03
VulnCheck KEV
2021-03-02
InTheWild.io
2021-03-02
ENISA EUVD
EUVD-2021-13641
Ransomware Use
Confirmed
CWE
CWE-502
Status
published
Products (4)
microsoft/exchange_server
2010 sp3
microsoft/exchange_server
2013 cumulative_update_22 (3 CPE variants)
microsoft/exchange_server
2016 cumulative_update_10 (12 CPE variants)
microsoft/exchange_server
2019 (9 CPE variants)
Published
Mar 03, 2021
KEV Added
Nov 03, 2021
Tracked Since
Feb 18, 2026